1. Field of the Invention
The present invention relates to an operation panel of an image forming apparatus or an image processing apparatus, such as a copying machine, as well as an operation panel of a mobile phone and the like. Specifically, the present invention relates to an electronic device including an operation panel for inputting and outputting information, and to an electronic device that can be suitably used in an image processing apparatus, an electronic calculating apparatus, and the like.
2. Description of the Related Art
As electronic devices, for example, liquid crystal displays of so-called calculators that use solar cells have been conventionally known (for reference, see Japanese Patent No. 3983911).
With such conventional liquid crystal displays, the calculation function and the display function can be performed, without charging means or the like, by using an electric power generated by the solar cell, as long as there is a luminance approximately at the level of a household illumination.
As shown in FIG. 1, in a so-called calculator 1 of the conventional type, its input part (operation part) 2, solar cell part 3 and display part 4 are arranged without overlapping each other. In a case of employing a display equipped with a solar cell, the solar cell part 3 and the display part 4 cannot be arranged in an overlapping manner because solar cells generate an electric power by absorbing visible light. Thus, there is a restriction on arrangement space.